The present invention relates to a ring carrier or "ring metal" for holding pages to a spine of a ring binder. In particular, the invention relates to a ring metal having a flexible cover sheet with diversely shaped regions along its length.
In a conventional ring binder a plurality of openable circular rings are arranged along a length of a ring metal which itself is secured to a spine or side panel of the cover of the ring binder. The rings are attached at their base ends to a respective one of a pair of hinged leaves which conform to a cross sectional "V" shape. At a central intersection between the two hinged leaves the hinge leaves provide interlacing tabs which prevent the leaves from becoming separated. Syrrounding the hinged leaves and extending the length of the ring metal is a resilient arcuate cover portion or "shield" having hooked lateral edge portion which clamp the hinged leaves into either an upright V configuration when the rings are open or a downward V configuration when the rings are closed. The resilient clasping of the shield provides for a "snapping" between the ring open and ring closed positions. Additionally, this resiliency holds the rings in a closed condition during usage.
It is a problem in designing ring binders that the interlacing tabs associated with the V-shaped leaves can overextend upwardly and foul or dent the shield from beneath, especially if the rings are forcibly spread apart.
It is known in the prior art to provide on the shield, between the rings along the length of the shield, a dimple or a downward indentation which creates an upward displacement stop for the hinged leaves. This stop is sized to limit the upward movement of the V-shaped hinged leaves to that position which prevents contact of the tabs with the underside of the shield. Such a design is disclosed in U.S. Pat. No. 4,552,478.
A re-enforced cover member having longitudinally arranged arcuate sections connected to, overlapping or blended into polygonal cross sections is not shown.